PowerFlex: How to Make "scini" devices available as multipath devices in Linux

Steps

1. Rename the 60-scini.rules file, as follows: 

   mv /etc/udev/rules.d/60-scini.rules /etc/udev/rules.d/20-scini.rules

2. Edit /etc/udev/rules.d/20-scini.rules and replace all its contents with the following:

   1. Red Hat Enterprise Linux:

      KERNEL=="scini*[!0-9]", SUBSYSTEM=="block", PROGRAM="/bin/emc/scaleio/drv_cfg --query_block_device_id --block_device $tempnode", SYMLINK+="disk/by-id/emc-vol-%c", ENV{ID_BUS}="scsi", ENV{ID_SERIAL}="%c"
      KERNEL=="scini*[0-9]", SUBSYSTEM=="block", PROGRAM="/bin/emc/scaleio/drv_cfg --query_block_device_id --block_device $tempnode", SYMLINK+="disk/by-id/emc-vol-%c-part%n"
      ACTION=="add", DEVPATH=="*scini*[!0-9]", RUN+="/bin/sh -c 'echo noop > /sys$DEVPATH/queue/scheduler'"
      ACTION=="add", DEVPATH=="*scini*[!0-9]", RUN+="/bin/sh -c 'echo 1024 > /sys$DEVPATH/queue/max_sectors_kb'"
      ACTION=="add", DEVPATH=="*scini*[!0-9]", RUN+="/bin/sh -c 'echo 512 > /sys$DEVPATH/queue/nr_requests'"

      Then, restart the "scini" service:

      For Red Hat Enterprise Linux 6.x:

      service scini restart

      For Red Hat Enterprise Linux 7.x:

      systemctl restart scini

   2. SuSE: For SLES 12 specifically, /etc/udev/rules.d/20-scini.rules must match this:

      KERNEL=="scini*[!0-9]", SUBSYSTEM=="block", PROGRAM="/bin/emc/scaleio/drv_cfg --query_block_device_id --block_device $tempnode", SYMLINK+="disk/by-id/emc-vol-%c", ENV{ID_BUS}="scsi", ENV{ID_SERIAL}="%c", ENV{ID_WWN}="%c"
      KERNEL=="scini*[0-9]", SUBSYSTEM=="block", PROGRAM="/bin/emc/scaleio/drv_cfg --query_block_device_id --block_device $tempnode", SYMLINK+="disk/by-id/emc-vol-%c-part%n"
      ACTION=="add", DEVPATH=="*scini*[!0-9]", RUN+="/bin/sh -c 'echo noop > /sys$DEVPATH/queue/scheduler'"
      ACTION=="add", DEVPATH=="*scini*[!0-9]", RUN+="/bin/sh -c 'echo 1024 > /sys$DEVPATH/queue/max_sectors_kb'"
      ACTION=="add", DEVPATH=="*scini*[!0-9]", RUN+="/bin/sh -c 'echo 512 > /sys$DEVPATH/queue/nr_requests'"

      And /etc/multipath.conf must contain:

      retain_attached_hw_handler "no"

      So if nothing else is defined in /etc/mutlipath.conf, it looks like:

      defaults {
          retain_attached_hw_handler "no"
      }

      Enable and start multipath:

      systemctl enable multipathd.service
      systemctl start multipathd.service

      Confirm that it is started:

      sles12:~ # systemctl status multipathd.service
      ● multipathd.service - Device-Mapper Multipath Device Controller
         Loaded: loaded (/usr/lib/systemd/system/multipathd.service; enabled; vendor preset: disabled)
         Active: active (running) since Sat 2019-05-18 16:15:26 EDT; 2min 8s ago
        Process: 852 ExecStartPre=/sbin/modprobe -a scsi_dh_alua scsi_dh_emc scsi_dh_rdac dm-multipath (code=exited, status=0/SUCCESS)
       Main PID: 856 (multipathd)
         Status: "idle"
          Tasks: 7 (limit: 512)
         CGroup: /system.slice/multipathd.service
                 └─856 /sbin/multipathd -d -s
      
      May 18 16:15:26 sles12 systemd[1]: Starting Device-Mapper Multipath Device Controller...
      May 18 16:15:26 sles12 multipathd[856]: path checkers start up
      May 18 16:15:26 sles12 systemd[1]: Started Device-Mapper Multipath Device Controller.
      May 18 16:15:33 sles12 multipathd[856]: scinia: add path (uevent)
      May 18 16:15:33 sles12 multipathd[856]: 1da395ed13deb1d5-54d2a00700000007: load table [0 33554432 multipath 0 0 1 1 service-time 0 1 1 253:0 1]
      May 18 16:15:33 sles12 multipathd[856]: 1da395ed13deb1d5-54d2a00700000007: event checker started
      May 18 16:15:33 sles12 multipathd[856]: scinia [253:0]: path added to devmap 1da395ed13deb1d5-54d2a00700000007

3. Map a PowerFlex volume to the Linux machine, run "multipath -ll" and you are now able to see your "scini" device represented as a multipath disk:

   mpathl (20086602f23bbab85df8eb89900000001) dm-10 ,
   size=24G features='0' hwhandler='0' wp=rw
   `-+- policy='round-robin 0' prio=1 status=active
   `- #:#:#:# scinia 252:0 active ready running